Traxler told police he was approached from behind as he climbed into his car by a man who demanded money and then hit him in the head with something.

The assailant then went through the congressman's pockets and escaped with $8, Nichols said. The robber apparently put the wallet back in Traxler's pocket before fleeing, he said.

Officials at Traxler's office said he had attended a dinner at a hotel north of the Capitol. The attack occurred about 1:30 a.m. No arrests have been made.

Assaults on people with congressional connections have been much publicized lately.

In recent months, Tom Barnes, an aide to Sen. Richard C. Shelby (D-Ala.), was shot to death as he walked near his home eight blocks from the Capitol. The wife of Sen. Kent Conrad (D-N.D.) was attacked by a gunman in December outside their Capitol Hill home. And earlier that month, a female House aide was stabbed.